Exosome: A New Player in Translational Nanomedicine

Current Challenges in the Development of Platelet-Rich Plasma-Based Therapies

Nowadays, biological therapies are booming and more of these formulations are coming to the market. Platelet-rich plasma, or PRP, is one of the most widely used biological therapies due to its ease of obtention and autologous character. Most of the techniques to obtain PRP are focusing on new processes and methods of optimization. However, not enough consideration is being given to modify the molecular components of PRP to generate more effective formulations with the aim of improving PRP treatments. Therefore, this review covers different novel PRP-obtaining methods that attempt to modify the molecular composition of the plasma.

Clinical Applications of Exosomes: A Critical Review

Exosomes, small membrane-bound vesicles secreted by cells, have gained significant attention for their therapeutic potential. Measuring 30-100 nm in diameter and derived from various cell types, exosomes play a crucial role in intercellular communication by transferring proteins, lipids, and RNA between cells. This review analyzes existing literature on the clinical applications of exosomes. We conducted a comprehensive search of peer-reviewed articles and clinical trial data to evaluate the benefits, limitations, and challenges of exosome-based therapies. Key areas of focus included regenerative medicine, cancer therapy, gene therapy, and diagnostic biomarkers. This review highlights the vast clinical applications of exosomes. In regenerative medicine, exosomes facilitate tissue repair and regeneration. In cancer therapy, exosomes can deliver therapeutic agents directly to tumor cells. In gene therapy, exosomes serve as vectors for gene delivery. As diagnostic biomarkers, they are useful in diagnosing various diseases. Challenges such as the isolation, purification, and characterization of exosomes were identified. Current clinical trials demonstrate the potential of exosome-based therapies, though they also reveal significant hurdles. Regulatory issues, including the need for standardization and validation of exosome products, are critical for advancing these therapies. While significant progress has been made in understanding exosome biology, further research is essential to fully unlock their clinical potential. Addressing challenges in isolation, purification, and regulatory standardization is crucial for their successful application in clinical practice. This review provides a concise overview of the clinical applications of exosomes, emphasizing both their therapeutic promise and the obstacles that need to be overcome.

Extracellular vesicles in nanomedicine and regenerative medicine: A review over the last decade

Small extracellular vesicles (sEVs) are known to be secreted by a vast majority of cells. These sEVs, specifically exosomes, induce specific cell-to-cell interactions and can activate signaling pathways in recipient cells through fusion or interaction. These nanovesicles possess several desirable properties, making them ideal for regenerative medicine and nanomedicine applications. These properties include exceptional stability, biocompatibility, wide biodistribution, and minimal immunogenicity. However, the practical utilization of sEVs, particularly in clinical settings and at a large scale, is hindered by the expensive procedures required for their isolation, limited circulation lifetime, and suboptimal targeting capacity. Despite these challenges, sEVs have demonstrated a remarkable ability to accommodate various cargoes and have found extensive applications in the biomedical sciences. To overcome the limitations of sEVs and broaden their potential applications, researchers should strive to deepen their understanding of current isolation, loading, and characterization techniques. Additionally, acquiring fundamental knowledge about sEVs origins and employing state-of-the-art methodologies in nanomedicine and regenerative medicine can expand the sEVs research scope. This review provides a comprehensive overview of state-of-the-art exosome-based strategies in diverse nanomedicine domains, encompassing cancer therapy, immunotherapy, and biomarker applications. Furthermore, we emphasize the immense potential of exosomes in regenerative medicine.

Enhancing of cerebral Abeta clearance by modulation of ABC transporter expression: a review of experimental approaches

Clearance of amyloid-beta (Aβ) from the brain is impaired in both early-onset and late-onset Alzheimer's disease (AD). Mechanisms for clearing cerebral Aβ include proteolytic degradation, antibody-mediated clearance, blood brain barrier and blood cerebrospinal fluid barrier efflux, glymphatic drainage, and perivascular drainage. ATP-binding cassette (ABC) transporters are membrane efflux pumps driven by ATP hydrolysis. Their functions include maintenance of brain homeostasis by removing toxic peptides and compounds, and transport of bioactive molecules including cholesterol. Some ABC transporters contribute to lowering of cerebral Aβ. Mechanisms suggested for ABC transporter-mediated lowering of brain Aβ, in addition to exporting of Aβ across the blood brain and blood cerebrospinal fluid barriers, include apolipoprotein E lipidation, microglial activation, decreased amyloidogenic processing of amyloid precursor protein, and restricting the entrance of Aβ into the brain. The ABC transporter superfamily in humans includes 49 proteins, eight of which have been suggested to reduce cerebral Aβ levels. This review discusses experimental approaches for increasing the expression of these ABC transporters, clinical applications of these approaches, changes in the expression and/or activity of these transporters in AD and transgenic mouse models of AD, and findings in the few clinical trials which have examined the effects of these approaches in patients with AD or mild cognitive impairment. The possibility that therapeutic upregulation of ABC transporters which promote clearance of cerebral Aβ may slow the clinical progression of AD merits further consideration.

Mesenchymal stem cell-derived exosomes decrease Hyperplasia in Psoriasis by inducing transforming growth factor β2 (TGF-β2)

BACKGROUND

Psoriasis, a chronic inflammatory skin disease, is increasingly effectively managed with the targeted immunotherapy; however, long-term immunotherapy carries health risks, and loss of response. Therefore, we need to develop the alternative treatment strategies. Mesenchymal stem/stromal cell (M.S.C.) exosomes stand out for their remarkable immunomodulatory properties, gaining widespread recognition. This study investigated whether M.S.C. exosomes can reduce psoriasis-induced hyperplasia by inducing Transforming Growth Factor beta 2 (TGF-beta2) signaling.

METHODOLOGY

Exosomes were isolated from M.S.C.s by ultracentrifugation. Then, scanning electron microscopy was used for the morphology of exosomes. To ascertain the exosome concentration, the Bradford test was used. To ascertain the cellular toxicity of exosomes in Human Umbilical Vein Endothelial Cells ( H.U.V.E.C), an MTT experiment was then conducted. Real-time PCR was used to quantify TGF beta2 expression levels, whereas an ELISA immunosorbent assay was used to determine the protein concentration of TGF beta2.

RESULTS

In this study, the exosomes of 15-30 nm in size that were uniform, and cup-shaped were isolated. Moreover, the IC50 value for this Treatment was calculated to be 181.750 µg/ml. The concentration of TGF-β2 gene in the target cells significantly increased following Treatment with the exosomes. Furthermore, the expression level of the studied gene significantly increased due to the Treatment.

CONCLUSION

Upregulating the expression of TGF-β2 in psoriatic cells via TGF-β2 signaling is one way exosomes can help reduce hyperplasia.

Engineered PDGFA-ligand-modified exosomes delivery T3 for demyelinating disease targeted therapy

Demyelination is a proper syndrome in plenty of central nervous system (CNS) diseases, which is the main obstacle to recovery and still lacks an effective treatment. To overcome the limitations of the brain-blood barrier on drug permeability, we modified an exosome secreted by neural stem cells (NSCs), which had transfected with lentivirus armed with platelet-derived growth factors A (PDGFA)-ligand. Through the in vivo and in vitro exosomes targeting test, the migration ability to the lesion areas and OPCs significantly improved after ligand modification. Furthermore, the targeted exosomes loaded with 3,5, 30-L-triiodothyronine (T3) have a critical myelination ability in CNS development, administrated to the cuprizone animal model treatment. The data shows that the novel drug vector loaded with T3 significantly promotes remyelination compared with T3 alone. At the same time, it improved the CNS microenvironment by reducing astrogliosis, inhibiting pro-inflammatory microglia, and alleviating axon damage. This investigation provides a straightforward strategy to produce a targeting exosome and indicates a possible therapeutic manner for demyelinating disease.

Mass Production of Rg1-Loaded Small Extracellular Vesicles Using a 3D Bioreactor System for Enhanced Cardioprotective Efficacy of Doxorubicin-Induced Cardiotoxicity

BACKGROUND

Small extracellular vesicles (sEVs) obtained from human umbilical cord mesenchymal stromal cells (MSCs) have shown cardioprotective efficacy in doxorubicin-induced cardiotoxicity (DIC). However, their clinical application is limited due to the low yield and high consumption. This study aims to achieve large-scale production of sEVs using a three-dimensional (3D) bioreactor system. In addition, sEVs were developed to deliver Ginsenoside Rg1 (Rg1), a compound derived from traditional Chinese medicine, Ginseng, that has cardioprotective properties but limited bioavailability, to enhance the treatment of DIC.

METHODS

The 3D bioreactor system with spinner flasks was used to expand human umbilical cord MSCs and collect MSC-conditioned medium. Subsequently, sEVs were isolated from the conditioned medium using differential ultra-centrifugation (dUC). The sEVs were loaded with Ginsenoside Rg1 by electroporation and evaluated for cardioprotective efficacy using Cell Counting Kit-8 (CCK-8) analysis, Annexin V/PI staining and live cell count of H9c2 cells under DIC.

RESULTS

Using the 3D bioreactor system with spinner flasks, the expansion of MSCs reached ~600 million, and the production of sEVs was up to 2.2 × 1012 particles in five days with significantly reduced bench work compared to traditional 2D flasks. With the optimized protocol, the Ginsenoside Rg1 loading efficiency of sEVs by electroporation was ~21%, higher than sonication or co-incubation. Moreover, Rg1-loaded sEVs had attenuated DOX-induced cardiotoxicity with reduced apoptosis compared to free Ginsenoside Rg1 or sEVs.

CONCLUSIONS

The 3D culture system scaled up the production of sEVs, which facilitated the Rg1 delivery and attenuated cardiomyocyte apoptosis, suggesting a potential treatment of DOX-induced cardiotoxicity.

Method to obtain a plasma rich in platelet- and plasma-growth factors based on water evaporation

Platelet-Rich Plasma, also known as PRP, is an autologous biologic product used in medicine as a treatment for tissue repair. Nowadays, the majority of PRP obtention methods enrich only platelets, not considering extraplatelet biomolecules, which take part in several cell processes. In the present work, a novel PRP preparation method was developed to obtain a PRP rich in both platelet and plasma extraplatelet molecules. The method is based on the evaporation of the water of the plasma using a rotary evaporator. With this new methodology an increase in plasmatic growth factors and, as a consequence, a better dermal fibroblast cell viability was achieved, compared to a standard PRP formulation. This novel PRP product obtained with this new methodology showed promising results in vitro as an improved PRP treatment in future application.

Nanoparticles Based on Natural Lipids Reveal Extent of Impacts of Designed Physical Characteristics on Biological Functions

Nanoparticles based on lipids (LNPs) are essential in pharmaceuticals and intercellular communication, and their design parameters span a diverse range of molecules and assemblies. In bridging the gap in insight between extracellular vesicles (EVs) and synthetic LNPs, one challenge is understanding their in-cell/in-body behavior when simultaneously assessing more than one physical characteristic. Herein, we demonstrate comprehensive evaluation of LNP behavior by using LNPs based on natural lipids (N-LNPs) with designed physical characteristics: size tuned using microfluidic methods, surface fluidity designed based on EV components, and stiffness tuned using biomolecules. We produce 12 types of N-LNPs having different physical characteristics─two sizes, three membrane fluidities, and two stiffnesses for in vitro evaluation─and evaluate cellular uptake vitality and endocytic pathways of N-LNPs based on the physical characteristics of N-LNPs. To reveal the extent of the impact of the predesigned physical characteristics of N-LNPs on cellular uptakes in vivo, we also carried out animal experiments with four types of N-LNPs having different sizes and fluidities. The use of N-LNPs has helped to clarify the extent of the impact of inextricably related, designed physical characteristics on transportation and provided a bidirectional guidepost for the streamlined design and understanding of the biological functions of LNPs.

Extracellular Vesicles and Exosomes: Novel Insights and Perspectives on Lung Cancer from Early Detection to Targeted Treatment

Lung cancer demands innovative approaches for early detection and targeted treatment. In addressing this urgent need, exosomes play a pivotal role in revolutionizing both the early detection and targeted treatment of lung cancer. Their remarkable capacity to encapsulate a diverse range of biomolecules, traverse biological barriers, and be engineered with specific targeting molecules makes them highly promising for both diagnostic markers and precise drug delivery to cancer cells. Furthermore, an in-depth analysis of exosomal content and biogenesis offers crucial insights into the molecular profile of lung tumors. This knowledge holds significant potential for the development of targeted therapies and innovative diagnostic strategies for cancer. Despite notable progress in this field, challenges in standardization and cargo loading persist. Collaborative research efforts are imperative to maximize the potential of exosomes and advance the field of precision medicine for the benefit of lung cancer patients.

Dual Role of Exosome in Neurodegenerative Diseases: A Review Study

INTRODUCTION

Extracellular vesicles (EVs) are one of the crucial means of intercellular communication, which takes many different forms. They are heterogeneous, secreted by a range of cell types, and can be generally classified into microvesicles and exosomes depending on their location and function. Exosomes are small EVs with diameters of about 30-150 nm and diverse cell sources.

METHODS

The MEDLINE/PubMed database was reviewed for papers written in English and publication dates of recent years, using the search string "Exosome" and "Neurodegenerative diseases."

RESULTS

The exosomes have attracted interest as a significant biomarker for a better understanding of disease development, gene silencing delivery, and alternatives to stem cell-based therapy because of their low-invasive therapeutic approach, repeatable distribution in the central nervous system (CNS), and high efficiency. Also, they are nanovesicles that carry various substances, which can have an impact on neural plasticity and cognitive functioning in both healthy and pathological circumstances. Therefore, exosomes are conceived as nanovesicles containing proteins, lipids, and nucleic acids. However, their composition varies considerably depending on the cells from which they are produced.

CONCLUSION

In the present review, we discuss several techniques for the isolation of exosomes from different cell sources. Furthermore, reviewing research on exosomes' possible functions as carriers of bioactive substances implicated in the etiology of neurodegenerative illnesses, we further examine them. We also analyze the preclinical and clinical research that shows exosomes to have therapeutic potential.

Exosomes: Methods for Isolation and Characterization in Biological Samples

Exosomes are small lipid bilayer-encapsulated nanosized extracellular vesicles of endosomal origin. Exosomes are secreted by almost all cell types and are a crucial player in intercellular communication. Exosomes transmit cellular information from donor to recipient cells in the form of proteins, lipids, and nucleic acids and influence several physiological and pathological responses. Due to their capacity to carry a variety of cellular cargo, low immunogenicity and cytotoxicity, biocompatibility, and ability to cross the blood-brain barrier, these nanosized vesicles are considered excellent diagnostic tools and drug-delivery vehicles. Despite their tremendous potential, the progress in therapeutic applications of exosomes is hindered by inadequate isolation techniques, poor characterization, and scarcity of specific biomarkers. The current research in the field is focused on overcoming these limitations. In this chapter, we have reviewed conventional exosome isolation and characterization methods and recent advancements, their advantages and limitations, persistent challenges in exosome research, and future directions.

Unveiling the Complex World of Extracellular Vesicles: Novel Characterization Techniques and Manufacturing Considerations

Extracellular vesicles (EVs) function as potent mediators of intercellular communication for many in vivo processes, contributing to both health and disease related conditions. Given their biological origins and diverse functionality from correspondingly unique "cargo" compositions, both endogenous and modified EVs are garnering attention as promising therapeutic modalities and vehicles for targeted therapeutic delivery applications. Their diversity in composition, however, has revealed a significant need for more comprehensive analytical-based characterization methods, and manufacturing processes that are consistent and scalable. In this review, we explore the dynamic landscape of EV research and development efforts, ranging from novel isolation approaches, to their analytical assessment through novel characterization techniques, and to their production by industrial-scale manufacturing process considerations. Expanding the horizon of these topics to EVs for in-human applications, we underscore the need for stringent development and adherence to Good Manufacturing Practice (GMP) guidelines. Wherein, the intricate interplay of raw materials, production in bioreactors, and isolation practices, along with analytical assessments compliant with the Minimal Information for Studies of Extracellular Vesicles (MISEV) guidelines, in conjunction with reference standard materials, collectively pave the way for standardized and consistent GMP production processes.

Schwann Cell-Derived Exosomal Vesicles: A Promising Therapy for the Injured Spinal Cord

Exosomes are nanoscale-sized membrane vesicles released by cells into their extracellular milieu. Within these nanovesicles reside a multitude of bioactive molecules, which orchestrate essential biological processes, including cell differentiation, proliferation, and survival, in the recipient cells. These bioactive properties of exosomes render them a promising choice for therapeutic use in the realm of tissue regeneration and repair. Exosomes possess notable positive attributes, including a high bioavailability, inherent safety, and stability, as well as the capacity to be functionalized so that drugs or biological agents can be encapsulated within them or to have their surface modified with ligands and receptors to imbue them with selective cell or tissue targeting. Remarkably, their small size and capacity for receptor-mediated transcytosis enable exosomes to cross the blood-brain barrier (BBB) and access the central nervous system (CNS). Unlike cell-based therapies, exosomes present fewer ethical constraints in their collection and direct use as a therapeutic approach in the human body. These advantageous qualities underscore the vast potential of exosomes as a treatment option for neurological injuries and diseases, setting them apart from other cell-based biological agents. Considering the therapeutic potential of exosomes, the current review seeks to specifically examine an area of investigation that encompasses the development of Schwann cell (SC)-derived exosomal vesicles (SCEVs) as an approach to spinal cord injury (SCI) protection and repair. SCs, the myelinating glia of the peripheral nervous system, have a long history of demonstrated benefit in repair of the injured spinal cord and peripheral nerves when transplanted, including their recent advancement to clinical investigations for feasibility and safety in humans. This review delves into the potential of utilizing SCEVs as a therapy for SCI, explores promising engineering strategies to customize SCEVs for specific actions, and examines how SCEVs may offer unique clinical advantages over SC transplantation for repair of the injured spinal cord.

Targeted therapy using engineered extracellular vesicles: principles and strategies for membrane modification

Extracellular vesicles (EVs) are 30-150 nm membrane-bound vesicles naturally secreted by cells and play important roles in intercellular communication by delivering regulatory molecules such as proteins, lipids, nucleic acids and metabolites to recipient cells. As natural nano-carriers, EVs possess desirable properties such as high biocompatibility, biological barrier permeability, low toxicity, and low immunogenicity, making them potential therapeutic delivery vehicles. EVs derived from specific cells have inherent targeting capacity towards specific cell types, which is yet not satisfactory enough for targeted therapy development and needs to be improved. Surface modifications endow EVs with targeting abilities, significantly improving their therapeutic efficiency. Herein, we first briefly introduce the biogenesis, composition, uptake and function of EVs, and review the cargo loading approaches for EVs. Then, we summarize the recent advances in surface engineering strategies of EVs, focusing on the applications of engineered EVs for targeted therapy. Altogether, EVs hold great promise for targeted delivery of various cargos, and targeted modifications show promising effects on multiple diseases.

Method Based on Ultrafiltration to Obtain a Plasma Rich in Platelet and Plasma Growth Factors

Platelet-Rich Plasma (PRP) is an autologous biological product which, due to its regenerative capacity, is currently used in different fields of medicine. This biological treatment has proven to be effective in numerous research studies due to its high content of growth factors released by platelets. However, the current systems used to obtain PRP do not enrich the growth factors and cytokines outside platelets. Considering this, the present work aims to develop a new technique by which all the biomolecules present in plasma are enriched. Thus, a new method based on ultrafiltration has been developed for the obtaining of the novel PRP. By this method, ultrafiltration of the plasma water is carried out using a 3KDa filtering unit. The results showed that the technique was able to concentrate extraplatelet factors, such as IGF-1 and HGF, in contrast with conventional plasmas. Thus, the cultured cells responded with increased viability to this new PRP. These results could provide a new approach to the treatment of injuries requiring regenerative medicine, potentially improving the outcomes of the conventional PRPs.

Application of exosome engineering modification in targeted delivery of therapeutic drugs

Cancer is the leading cause of premature death in humans. Scientists have developed several therapeutic drugs for cancer treatment. However, drug delivery faces many problems. First, traditional drugs do not target tumors and are prone to causing significant toxic side effects. Second, suitable drug carriers are essential for improving drug delivery to tumors or circulating cancer cells. Exosomes are natural extracellular vesicles with low immunogenicity and prolonged blood circulation in vivo. These characteristics render exosomes ideal drug carriers. This review highlights the properties of exosomes and mechanisms of exosome biogenesis. It also summarizes the engineering modification methods for enhancing exosome yield, targeting, and drug-loading capacity.

A Review Study of the Participation of Late Domains in Sorting and Transport of Viral Factors to Exosomes

Cellular communication depends heavily on the participation of vesicular systems generated by most cells of an organism. Exosomes play central roles in this process. Today, these vesicles have been characterized, and it has been determined that the cargo they transport is not within a random system. In fact, it depends on various molecular signals and the recruitment of proteins that participate in the biogenesis of exosomes. It has also been shown that multiple viruses can recruit these vesicles to transport viral factors such as genomes or proteins. It has been shown that the late domains present in viral proteins are critical for the exosomal selection and biogenesis systems to recognize these viral proteins and introduce them into the exosomes. In this review, the researchers discuss the evidence related to the characterization of these late domains and their role in exosome recruitment during viral infection.

Exosomal MicroRNA and Protein Profiles of Hepatitis B Virus-Related Hepatocellular Carcinoma Cells

Infection with hepatitis B virus (HBV) is a main risk factor for hepatocellular carcinoma (HCC). Extracellular vesicles, such as exosomes, play an important role in tumor development and metastasis, including regulation of HBV-related HCC. In this study, we have characterized exosome microRNA and proteins released in vitro from hepatitis B virus (HBV)-related HCC cell lines SNU-423 and SNU-182 and immortalized normal hepatocyte cell lines (THLE2 and THLE3) using microRNA sequencing and mass spectrometry. Bioinformatics, including functional enrichment and network analysis, combined with survival analysis using data related to HCC in The Cancer Genome Atlas (TCGA) database, were applied to examine the prognostic significance of the results. More than 40 microRNAs and 200 proteins were significantly dysregulated (p < 0.05) in the exosomes released from HCC cells in comparison with the normal liver cells. The functional analysis of the differentially expressed exosomal miRNAs (i.e., mir-483, mir-133a, mir-34a, mir-155, mir-183, mir-182), their predicted targets, and exosomal differentially expressed proteins (i.e., POSTN, STAM, EXOC8, SNX9, COL1A2, IDH1, FN1) showed correlation with pathways associated with HBV, virus activity and invasion, exosome formation and adhesion, and exogenous protein binding. The results from this study may help in our understanding of the role of HBV infection in the development of HCC and in the development of new targets for treatment or non-invasive predictive biomarkers of HCC.

Exosomes in brain diseases: Pathogenesis and therapeutic targets

Exosomes are extracellular vesicles with diameters of about 100 nm that are naturally secreted by cells into body fluids. They are derived from endosomes and are wrapped in lipid membranes. Exosomes are involved in intracellular metabolism and intercellular communication. They contain nucleic acids, proteins, lipids, and metabolites from the cell microenvironment and cytoplasm. The contents of exosomes can reflect their cells' origin and allow the observation of tissue changes and cell states under disease conditions. Naturally derived exosomes have specific biomolecules that act as the "fingerprint" of the parent cells, and the contents changed under pathological conditions can be used as biomarkers for disease diagnosis. Exosomes have low immunogenicity, are small in size, and can cross the blood-brain barrier. These characteristics make exosomes unique as engineering carriers. They can incorporate therapeutic drugs and achieve targeted drug delivery. Exosomes as carriers for targeted disease therapy are still in their infancy, but exosome engineering provides a new perspective for cell-free disease therapy. This review discussed exosomes and their relationship with the occurrence and treatment of some neuropsychiatric diseases. In addition, future applications of exosomes in the diagnosis and treatment of neuropsychiatric disorders were evaluated in this review.

EVs vs. EVs: MSCs and Tregs as a source of invisible possibilities

Extracellular vesicles (EVs) are produced by various cells and exist in most biological fluids. They play an important role in cell-cell signaling, immune response, and tumor metastasis, and also have theranostic potential. They deliver many functional biomolecules, including DNA, microRNAs (miRNA), messenger RNA (mRNA), long non-coding RNA (lncRNA), lipids, and proteins, thus affecting different physiological processes in target cells. Decreased immunogenicity compared to liposomes or viral vectors and the ability to cross through physiological barriers such as the blood-brain barrier make them an attractive and innovative option as diagnostic biomarkers and therapeutic carriers. Here, we highlighted two types of cells that can produce functional EVs, namely, mesenchymal stem/stromal cells (MSCs) and regulatory T cells (Tregs), discussing MSC/Treg-derived EV-based therapies for some specific diseases including acute respiratory distress syndrome (ARDS), autoimmune diseases, and cancer.

Hybrid exosomes, exosome-like nanovesicles and engineered exosomes for therapeutic applications

Exosomes are endosome-derived nanovesicles involved in cellular communication. They are natural nanocarriers secreted by various cells, making them suitable candidates for diverse drug delivery and therapeutic applications from a material standpoint. They have a phospholipid bilayer decorated with functional molecules and an enclosed parental matrix, which has attracted interest in developing designer/hybrid engineered exosome nanocarriers. The structural versatility of exosomes allows the modification of their original configuration using various methods, including genetic engineering, chemical procedures, physical techniques, and microfluidic technology, to load exosomes with additional cargo for expanded biomedical applications. Exosomes show enormous potential for overcoming the limitations of conventional nanoparticle-based techniques in targeted therapy. This review highlights the exosome sources, characteristics, state of the art in the field of hybrid exosomes, exosome-like nanovesicles and engineered exosomes as potential cargo delivery vehicles for therapeutic applications.

Impact of local predisposing/precipitating factors and systemic drivers on peri‐implant diseases

BACKGROUND

Strong evidence suggests the infectious nature of peri-implant diseases occurring in susceptible hosts. Epidemiological reports, though, indicate that peri-implantitis is a site-specific entity. Hence, the significance of local factors that may predispose/precipitate plaque accumulation and the impact of systemic drivers that alter the immune response are relevant in the prevention and management of peri-implant disorders.

PURPOSE

The purpose of the present review is to shed light on the significance of local and systemic factors on peri-implant diseases, making special emphasis on the associations with peri-implantitis.

METHODS

The biologic plausibility and supporting evidence aiming at providing a concluding remark were explored in the recent scientific literature for local predisposing/precipitating factors and systemic drivers related to peri-implant diseases.

RESULTS

Local predisposing factors such as soft tissue characteristics, implant position and prosthetic design proved being strongly associated with the occurrence of peri-implant diseases. Hard tissue characteristics, however, failed to demonstrate having a direct association with peri-implant diseases. Robust data points toward the strong link between residual sub-mucosal cement and peri-implant diseases, while limited data suggests the impact of residual sub-mucosal floss and peri-implantitis. Systemic drivers/habits such as hyperglycemia and smoking showed a strong negative impact on peri-implantitis. However, there is insufficient evidence to claim for any link between metabolic syndrome, atherosclerotic cardiovascular disease, and obesity and peri-implant diseases.

CONCLUSION

Local predisposing/precipitating factors and systemic drivers may increase the risk of peri-implant diseases. Therefore, comprehensive anamnesis of the patients, educational/motivational programs and exhaustive prosthetically-driven treatment planning must be fostered aiming at reducing the rate of biological complications in implant dentistry.

An optimized exosome production strategy for enhanced yield while without sacrificing cargo loading efficiency

Background

Exosome mediated mRNA delivery is a promising strategy for the treatment of multiple diseases. However, the low yield of exosomes is a bottleneck for clinical translation. In this study, we boosted exosome production via simultaneously reducing the expression of genes inhibiting exosome biogenesis and supplementing the culture medium with red cell membrane components.

Results

Among the candidate genes, knocking down of Rab4 was identified to have the highest efficacy in promoting exosome biogenesis while without any obvious cytotoxicity. Additionally, supplementing red cell membrane particles (RCMPs) in the culture medium further promoted exosome production. Combination of Rab4 knockdown and RCMP supplement increased exosome yield up to 14-fold. As a proof-of-concept study, low-density lipoprotein receptor (Ldlr) mRNA was forced expressed in the exosome donor cells and passively encapsulated into the exosomes during biogenesis with this strategy. Though exosome production per cell increased, the booster strategy didn’t alter the loading efficiency of therapeutic Ldlr mRNA per exosome. Consistently, the therapeutic exosomes derived by the strategy alleviated liver steatosis and atherosclerosis in Ldlr^−/− mice, similar as the exosomes produced by routine methods.

Conclusions

Together, the proposed exosome booster strategy conquers the low yield bottleneck to some extent and would certainly facilitate the clinical translation of exosomes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-022-01668-3.

Effect of different molecular weight and terminal group PLGA on docetaxel nanoparticles: Characterization and cytotoxic activity of castration-resistant prostate cancer cells

The choice of polymer and its compatibility with drug used determine the fate of nanoparticle in therapy. There has been limited sources about effect of resomer differentiation in nanoparticle related with physical and chemical properties and also biological activities of product. Therefore, we aimed to formulate docetaxel loaded polylactic-co-glycolic acid nanoparticles with different molecular weights (Resomer 502 and 504) and terminal groups (Resomer 502H and 504H) and to investigate the effect of these resomers on nanoparticle character, prostate cancer and healthy cells. Docetaxel loaded PLGA nanoparticles were prepared by single emulsion solvent evaporation method. Surface characterizations were carried out by zeta sizer and scanning electron microscopy. Encapsulation efficiency, in vitro drug release profiles and cytotoxic activity were determined. Main effect on the surface morphology of nanoparticles was the molecular weight of the polymer. In groups with acid terminal function have higher encapsulation and reaction efficiency. In all formulations, in vitro release was observed after 334 hours at pH 7.4 and 240 hours at pH 5.6. Also, the groups with high molecular weight showed selective cytotoxicity. These resomers especially RG 504 and RG 504H have potential to be used as a low-dose and high-efficiency extended-release drug delivery system in the treatment of prostate cancer.

Advances in the pathogenesis and clinical application prospects of tumor biomolecules in keloid

Keloid scarring is a kind of pathological healing manifestation after skin injury and possesses various tumor properties, such as the Warburg effect, epithelial-mesenchymal transition (EMT), expression imbalances of apoptosis-related genes and the presence of stem cells. Abnormal expression of tumor signatures is critical to the initiation and operation of these effects. Although previous experimental studies have recognized the potential value of a single or several tumor biomolecules in keloids, a comprehensive evaluation system for multiple tumor signatures in keloid scarring is still lacking. This paper aims to summarize tumor biomolecules in keloids from the perspectives of liquid biopsy, genetics, proteomics and epigenetics and to investigate their mechanisms of action and feasibility from bench to bedside. Liquid biopsy is suitable for the early screening of people with keloids due to its noninvasive and accurate performance. Epigenetic biomarkers do not require changes in the gene sequence and their reversibility and tissue specificity make them ideal therapeutic targets. Nonetheless, given the ethnic specificity and genetic predisposition of keloids, more large-sample multicenter studies are indispensable for determining the prevalence of these signatures and for establishing diagnostic criteria and therapeutic efficacy estimations based on these molecules.

Exosomes Derived From Umbilical Cord Mesenchymal Stem Cells Treat Cutaneous Nerve Damage and Promote Wound Healing

Wound repair is a key step in the treatment of skin injury caused by burn, surgery, and trauma. Various stem cells have been proven to promote wound healing and skin regeneration as candidate seed cells. Therefore, exosomes derived from stem cells are emerging as a promising method for wound repair. However, the mechanism by which exosomes promote wound repair is still unclear. In this study, we reported that exosomes derived from umbilical cord mesenchymal stem cells (UC-MSCs) promote wound healing and skin regeneration by treating cutaneous nerve damage. The results revealed that UC-MSCs exosomes (UC-MSC-Exo) promote the growth and migration of dermal fibroblast cells. In in vitro culture, dermal fibroblasts could promote to nerve cells and secrete nerve growth factors when stimulated by exosomes. During the repair process UC-MSC-Exo accelerated the recruitment of fibroblasts at the site of trauma and significantly enhanced cutaneous nerve regeneration in vivo. Interestingly, it was found that UC-MSC-Exo could promote wound healing and skin regeneration by recruiting fibroblasts, stimulating them to secrete nerve growth factors (NGFs) and promoting skin nerve regeneration. Therefore, we concluded that UC-MSC-Exo promote cutaneous nerve repair, which may play an important role in wound repair and skin regeneration.

Mesenchymal stem cell-derived exosomes: A novel and potential remedy for cutaneous wound healing and regeneration

Poor healing of cutaneous wounds is a common medical problem in the field of traumatology. Due to the intricate pathophysiological processes of wound healing, the use of conventional treatment methods, such as chemical molecule drugs and traditional dressings, have been unable to achieve satisfactory outcomes. Within recent years, explicit evidence suggests that mesenchymal stem cells (MSCs) have great therapeutic potentials on skin wound healing and regeneration. However, the direct application of MSCs still faces many challenges and difficulties. Intriguingly, exosomes as cell-secreted granular vesicles with a lipid bilayer membrane structure and containing specific components from the source cells may emerge to be excellent substitutes for MSCs. Exosomes derived from MSCs (MSC-exosomes) have been demonstrated to be beneficial for cutaneous wound healing and accelerate the process through a variety of mechanisms. These mechanisms include alleviating inflammation, promoting vascularization, and promoting proliferation and migration of epithelial cells and fibroblasts. Therefore, the application of MSC-exosomes may be a promising alternative to cell therapy in the treatment of cutaneous wounds and could promote wound healing through multiple mechanisms simultaneously. This review will provide an overview of the role and the mechanisms of MSC-derived exosomes in cutaneous wound healing, and elaborate the potentials and future perspectives of MSC-exosomes application in clinical practice.

Extracellular Vesicles as Novel Drug-Delivery Systems through Intracellular Communications

Since it has been reported that extracellular vesicles (EVs) carry cargo using cell-to-cell comminication according to various in vivo situations, they are exprected to be applied as new drug-delivery systems (DDSs). In addition, non-coding RNAs, such as microRNAs (miRNAs), have attracted much attention as potential biomarkers in the encapsulated extracellular-vesicle (EV) form. EVs are bilayer-based lipids with heterogeneous populations of varying sizes and compositions. The EV-mediated transport of contents, which includes proteins, lipids, and nucleic acids, has attracted attention as a DDS through intracellular communication. Many reports have been made on the development of methods for introducing molecules into EVs and efficient methods for introducing them into target vesicles. In this review, we outline the possible molecular mechanisms by which miRNAs in exosomes participate in the post-transcriptional regulation of signaling pathways via cell–cell communication as novel DDSs, especially small EVs.

Conventional and Nonconventional Sources of Exosomes-Isolation Methods and Influence on Their Downstream Biomedical Application

Despite extensive study of extracellular vesicles (EVs), specifically exosomes (EXs) as biomarkers, important modulators of physiological or pathological processes, or therapeutic agents, relatively little is known about nonconventional sources of EXs, such as invertebrate or plant EXs, and their uses. Likewise, there is no clear information on the overview of storage conditions and currently used isolation methods, including new ones, such as microfluidics, which fundamentally affect the characterization of EXs and their other biomedical applications. The purpose of this review is to briefly summarize conventional and nonconventional sources of EXs, storage conditions and typical isolation methods, widely used kits and new "smart" technologies with emphasis on the influence of isolation techniques on EX content, protein detection, RNA, mRNA and others. At the same time, attention is paid to a brief overview of the direction of biomedical application of EXs, especially in diagnostics, therapy, senescence and aging and, with regard to the current situation, in issues related to Covid-19.

Mechanism and clinical value of exosomes and exosomal contents in regulating solid tumor radiosensitivity

Radiotherapy is among the routine treatment options for malignant tumors. And it damages DNA and other cellular organelles in target cells by using ionizing radiation produced by various rays, killing the cells. In recent years, multiple studies have demonstrated that exosomes are mechanistically involved in regulating tumor formation, development, invasion and metastasis, and immune evasion. The latest research shows that radiation can affect the abundance and composition of exosomes as well as cell-to-cell communication. In the environment, exosome-carried miRNAs, circRNA, mRNA, and proteins are differentially expressed in cancer cells, while these molecules play a role in numerous biological processes, including the regulation of oncogene expression, mediation of signaling pathways in cancer cells, remodeling of tumor-related fibroblasts, regulation of cell radiosensitivity, and so forth. Therefore, elucidation of the mechanism underlying the role of exosomes in radiotherapy of malignant tumors is crucial for improving the efficacy of radiotherapy. This review will summarize the research advances in radiosensitivity of malignant tumors related to exosomes.

Insight into Extracellular Vesicle-Cell Communication: From Cell Recognition to Intracellular Fate

Extracellular vesicles (EVs) are heterogamous lipid bilayer-enclosed membranous structures secreted by cells. They are comprised of apoptotic bodies, microvesicles, and exosomes, and carry a range of nucleic acids and proteins that are necessary for cell-to-cell communication via interaction on the cells surface. They initiate intracellular signaling pathways or the transference of cargo molecules, which elicit pleiotropic responses in recipient cells in physiological processes, as well as pathological processes, such as cancer. It is therefore important to understand the molecular means by which EVs are taken up into cells. Accordingly, this review summarizes the underlying mechanisms involved in EV targeting and uptake. The primary method of entry by EVs appears to be endocytosis, where clathrin-mediated, caveolae-dependent, macropinocytotic, phagocytotic, and lipid raft-mediated uptake have been variously described as being prevalent. EV uptake mechanisms may depend on proteins and lipids found on the surfaces of both vesicles and target cells. As EVs have been shown to contribute to cancer growth and progression, further exploration and targeting of the gateways utilized by EVs to internalize into tumor cells may assist in the prevention or deceleration of cancer pathogenesis.

Exosome-Laden Hydrogels: A Novel Cell-free Strategy for In-situ Bone Tissue Regeneration

In-situ bone tissue regeneration, which harnesses cell external microenvironment and their regenerative potential to induce cell functions and bone reconstruction through some special properties of biomaterials, has been deeply developed. In which, hydrogel was widely applied due to its 3D network structure with high water absorption and mimicking native extracellular matrix (ECM). Additionally, exosomes can participate in a variety of physiological processes such as cell differentiation, angiogenesis and tissue repair. Therefore, a novel cell-free tissue engineering (TE) using exosome-laden hydrogels has been explored and developed for bone regeneration in recent years. However, related reviews in this field are limited. Therefore, we elaborated on the shortcomings of traditional bone tissue engineering, the challenges of exosome delivery and emphasized the advantages of exosome-laden hydrogels for in-situ bone tissue regeneration. The encapsulation strategies of hydrogel and exosomes are listed, and the research progress and prospects of bioactive hydrogel composite system for continuous delivery of exosomes for in-situ bone repair are also discussed in this review.

Use of patent information to characterize trends in the therapeutic applications of extracellular vesicles derived from mesenchymal stem cells (MSC-EVs)

Extracellular vesicles derived from mesenchymal stromal cells (MSC-EVs) are gaining interest for medical purposes. The promising therapeutic effects exhibited in both preclinical and clinical studies suggest that they may become an alternative for certain applications to cell-based therapies, which are subjected to stricter regulations. The commercial exploitation of these candidates requires a proper patent strategy from both the industry and public research organizations. Here, we raise a global patent literature analysis to identify key players and therapeutic applications in the field. Our results show an increasing rate of patent publications since 2009, with Asia (specifically China) leading the patenting activity. The therapeutic use of MSC-EVs within patent literature covers a wide range of diseases, in which "Dermal and Wounds", "Neurology" and "Cardiovascular" are the main therapeutic areas. Moreover, most of these patents include "product-by-process" claims, since the therapeutic effects of MSC-EVs could be influenced by their manufacturing process. Our results follow scientific and clinical literature trends.

Plasma exosomal proteomic studies of corneal epithelial injury in diabetic and non-diabetic group

OBJECTIVE

Diabetic Keratopathy (DK) is one of the significant complications of type II diabetes (T2DM) with pathogenesis not yet clarified. Since hyperglycemia is able to change the protein components contained in plasma exosomes, liquid chromatography-tandem mass spectrometry (LC-MS/MS) is considered as feasible to analyze the expression of plasma exosomal proteins in patients with T2DM and non-diabetic patients respectively, find critical biological markers, and explore the mechanism of DK as well as potential therapeutic targets.

METHOD

Blood and clinical information of corneal epithelial injury in a diabetic group (the study group) and a non-diabetic group (the control group), who were patients admitted to the Department of Ophthalmology, Yangpu Hospital, Tongji University School of Medicine from July 2020 to November 2020, were collected. The qEV size exclusion method was adopted to separate exosomes from plasma. The exosomes were then identified through transmission electron microscopy (TEM), nanoparticle tracking analyzer (NTA), and Western blot. The plasma exosomes of the study group and the control group were quantitatively analyzed by proteomics. A bioinformatics method is utilized to screen differential proteins and the expression of the differential proteins was verified by Western blot.

RESULT

TEM indicated that the exosomes had a double-concave disc-like appearance, with a size of about 100 nm, and Western blot expressed as CD63 and TSG101. The plasma exosomes of the study group and the control group were analyzed by quantitative proteomics with a total number of 952 proteins detected of which 245 proteins existed in the ExoCarta exosomal protein database. Through adoption of P-value to screen credible differential proteins, the heat map displayed 28 differential proteins, 7 upregulated proteins, and 21 downregulated proteins; the volcano map displayed 7 upregulated proteins and 22 downregulated proteins; the PPI interaction map displayed 12 upregulated proteins and 18 downregulated proteins. Through GO enrichment analysis, it was identified that the differential protein participated in the main biological processes and was involved in regulating the cell's stimulation response to insulin, the insulin receptor signaling pathway, and the activity of glycosylphosphatidylinositol phospholipase D as well as anti-oxidation. The enriched cell components include main components such as exosomes, blood particles, and cytoplasm. KEGG enrichment analysis indicated that the target protein FLOT2 was mainly concentrated in insulin-related signaling pathways. Western blot indicated that the expression of FLOT2 in the study group was lower compared with the control group while the expression of Exo70 was higher.

CONCLUSION

Proteomic analysis of the study group and the control group displayed a variety of proteins in plasma exosomes. The downregulated protein FLOT2 in the study group was closely related to the occurrence, development, and complication of DK in T2DM patients. The expression status of plasma FLOT2 protein in T2DM patients is expected to be a biomarker for diagnosing and monitoring of DK.

Liquid biopsy approach to pancreatic cancer

Pancreatic cancer (PC) continues to pose a major clinical challenge. There has been little improvement in patient survival over the past few decades, and it is projected to become the second leading cause of cancer mortality by 2030. The dismal 5-year survival rate of less than 10% after the diagnosis is attributable to the lack of early symptoms, the absence of specific biomarkers for an early diagnosis, and the inadequacy of available chemotherapies. Most patients are diagnosed when the disease has already metastasized and cannot be treated. Cancer interception is vital, actively intervening in the malignization process before the development of a full-blown advanced tumor. An early diagnosis of PC has a dramatic impact on the survival of patients, and improved techniques are urgently needed to detect and evaluate this disease at an early stage. It is difficult to obtain tissue biopsies from the pancreas due to its anatomical position; however, liquid biopsies are readily available and can provide useful information for the diagnosis, prognosis, stratification, and follow-up of patients with PC and for the design of individually tailored treatments. The aim of this review was to provide an update of the latest advances in knowledge on the application of carbohydrates, proteins, cell-free nucleic acids, circulating tumor cells, metabolome compounds, exosomes, and platelets in blood as potential biomarkers for PC, focusing on their clinical relevance and potential for improving patient outcomes.

Telocytes and their structural relationships with surrounding cell types in the skin of silky fowl by immunohistochemistrical, transmission electron microscopical and morphometric analysis

Telocytes (TCs), a novel type of interstitial cells, were identified in various animals. Since TCs have not observed in avian skin, hence, we carried out immunohistochemistrical and transmission electron microscopical studies in the skin of the silky fowl to investigate the TCs. TCs appear as CD34, c-Kit, and PDGFRα immunopositive. The elongated TCs with 2 long and thin telopodes (Tps) are located in the dermis. Generally, a TC possesses a fusiform, ovoid and polygonal cell body with 2 Tps (lengths = 5.27-21.85 μm), which are uneven in thickness including thick sections - podoms (diameters = 0.40-0.47 μm) and thin sections - podomers (diameters = 0.03-0.04 μm). TCs/Tps are observed frequently in close proximity to neighboring cell types/structures, such as adipocytes, collagen fibers, and capillaries. Under a magnified field, homocellular TCs/Tps contacts are observed through gap junctions (distances = 0.01-0.05 μm), whereas some of TCs/Tps have heterocellular close contacts by point contacts with surrounding cells, including stem cells and melanocytes. The multivisicular bodies, especially exosomes (diameters = 0.09-0.23 μm) releasing from TCs/Tps are observed in close proximity to TCs/Tps. Our results illustrated that the novel type of interstitial cells - TCs are present in the dermis of the silky fowl, and they have special structural relationships with surrounding cell types. The study provides histological evidence for TCs involvement in intercellular communication, skin regeneration, and pigmentogenesis in avian skin.

Exosomes and Micro-RNAs in Aging Process

Exosomes are the main actors of intercellular communications and have gained great interest in the new cell-free regenerative medicine. These nanoparticles are secreted by almost all cell types and contain lipids, cytokines, growth factors, messenger RNA, and different non-coding RNA, especially micro-RNAs (mi-RNAs). Exosomes' cargo is released in the neighboring microenvironment but is also expected to act on distant tissues or organs. Different biological processes such as cell development, growth and repair, senescence, migration, immunomodulation, and aging, among others, are mediated by exosomes and principally exosome-derived mi-RNAs. Moreover, their therapeutic potential has been proved and reinforced by their use as biomarkers for disease diagnostics and progression. Evidence has increasingly shown that exosome-derived mi-RNAs are key regulators of age-related diseases, and their involvement in longevity is becoming a promising issue. For instance, mi-RNAs such as mi-RNA-21, mi-RNA-29, and mi-RNA-34 modulate tissue functionality and regeneration by targeting different tissues and involving different pathways but might also interfere with long life expectancy. Human mi-RNAs profiling is effectively related to the biological fluids that are reported differently between young and old individuals. However, their underlying mechanisms modulating cell senescence and aging are still not fully understood, and little was reported on the involvement of mi-RNAs in cell or tissue longevity. In this review, we summarize exosome biogenesis and mi-RNA synthesis and loading mechanism into exosomes' cargo. Additionally, we highlight the molecular mechanisms of exosomes and exosome-derived mi-RNA regulation in the different aging processes.

Extracellular Vesicles in Immune System Regulation and Type 1 Diabetes: Cell-to-Cell Communication Mediators, Disease Biomarkers, and Promising Therapeutic Tools

Extracellular vesicles (EVs) are generated by cells of origin through complex molecular mechanisms and released into extracellular environment. Hence, the presence of EVs has been described in multiple biological fluids and in most cases their molecular cargo, which includes non-coding RNAs (ncRNA), messenger RNAs (mRNA), and proteins, has been reported to modulate distinct biological processes. EVs release and their molecular cargo have been demonstrated to be altered in multiple diseases, including autoimmune diseases. Notably, numerous evidence showed a relevant crosstalk between immune system and interacting cells through specific EVs release. The crosstalk between insulin-producing pancreatic β cells and immune system through EVs bidirectional trafficking has yet started to be deciphered, thus uncovering an intricate communication network underlying type 1 diabetes (T1D) pathogenesis. EVs can also be found in blood plasma or serum. Indeed, the assessment of circulating EVs cargo has been shown as a promising advance in the detection of reliable biomarkers of disease progression. Of note, multiple studies showed several specific cargo alterations of EVs collected from plasma/serum of subjects affected by autoimmune diseases, including T1D subjects. In this review, we discuss the recent literature reporting evidence of EVs role in autoimmune diseases, specifically focusing on the bidirectional crosstalk between pancreatic β cells and immune system in T1D and highlight the relevant promising role of circulating EVs as disease biomarkers.

Anti-inflammatory and M2 macrophage polarization-promoting effect of mesenchymal stem cell-derived exosomes

Mesenchymal stem cells (MSCs) are multipotent cells beneficial in regenerative medicine and tissue repair. The therapeutic potential of MSCs for inflammatory diseases and conditions is partly due to secreted exosomes. Exosomes are one group of extracellular vesicles with 50-150 nm in diameter. They can carry numerous molecules and introduce them to the recipient cells to produce various biological effects. Macrophages are classified into M1 and M2 subtypes based on their activation states. M1 macrophages release pro-inflammatory factors like tumor necrosis factoralfa (TNF-α), interleukin1alfa (IL-1α), interleukin1beta (IL-1β), interleukin6 (IL-6), C-X-C motif chemokine ligand 9 (CXCL9), and C-X-C motif chemokine ligand 10 (CXCL10), while M2 macrophages secrete anti-inflammatory mediators including interleukin10 (IL-10), transforming growth factor beta (TGF-β), C-C motif chemokine ligand 1 (CCL1), C-C motif chemokine ligand 17 (CCL17), C-C motif chemokine ligand 18 (CCL18), and C-C motif chemokine ligand 22 (CCL22). This review summarizes the effect of MSC-derived exosomes in the polarization of M2 macrophages, which their anti-inflammatory and immunomodulatory properties are potentially effective in inflammation diseases and conditions such as central nervous system (CNS) diseases, autoimmune diseases, inflammatory bowel disease, cardiomyopathy, graftversushost disease, kidney, liver, lung, and skin injuries.

Exosomes contribution in COVID-19 patients' treatment

Adipose cell-free derivatives have been recently gaining attention as potential therapeutic agents for various human diseases. In this context, mesenchymal stromal/stem cells (MSCs), adipocyte mesenchymal stem cells (Ad-MSCs) and adipose-derived stem cells (ADSC) possessing potent immunomodulatory activities are proposed as a therapeutic option for the treatment of coronavirus disease 2019 (COVID-19). The COVID-19 represents a global concern of public health caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in which there is not actually any specific therapy. MSCs exert an immunomodulation effect due to the secretion of endogenous factors, such as vascular endothelial growth factor (VEGF), insulin growth factor (IGF), and nerve growth factor (NGF), transforming growth factor (TGF)-β and growth differentiation factor (GDF)-11. Recent reports are promising for further studies and clinical applications of ADSCs and Ad-MSCs in COVID-19 patients. Experimental and clinical studies are exploring the therapeutic potential of both MSCs and derived-exosomes in moderating the morbidity and mortality of COVID-19. In this field, more preclinical and clinical studies are warranted to find an effective treatment for the patients suffering from COVID-19 infection.

Perspectives of Microscopy Methods for Morphology Characterisation of Extracellular Vesicles from Human Biofluids

Extracellular vesicles (EVs) are nanometric membranous structures secreted from almost every cell and present in biofluids. Because EV composition reflects the state of its parental tissue, EVs possess an enormous diagnostic/prognostic potential to reveal pathophysiological conditions. However, a prerequisite for such usage of EVs is their detailed characterisation, including visualisation which is mainly achieved by atomic force microscopy (AFM) and electron microscopy (EM). Here we summarise the EV preparation protocols for AFM and EM bringing out the main challenges in the imaging of EVs, both in their natural environment as biofluid constituents and in a saline solution after EV isolation. In addition, we discuss approaches for EV imaging and identify the potential benefits and disadvantages when different AFM and EM methods are applied, including numerous factors that influence the morphological characterisation, standardisation, or formation of artefacts. We also demonstrate the effects of some of these factors by using cerebrospinal fluid as an example of human biofluid with a simpler composition. Here presented comparison of approaches to EV imaging should help to estimate the current state in morphology research of EVs from human biofluids and to identify the most efficient pathways towards the standardisation of sample preparation and microscopy modes.

The Role of Exosomes Derived From Mesenchymal Stromal Cells in Dermatology

The skin is the largest organ of the human body and its main functions include providing protection from external harmful agents, regulating body temperature, and homeostatic maintenance. Skin injuries can damage this important barrier and its functions so research focuses on approaches to accelerate wound healing and treat inflammatory skin diseases. Due to their regenerative and immunomodulatory properties, mesenchymal stromal cells (MSCs) have been reported to play a significant role in skin repair and regeneration. However, it seems that the secretome of these cells and exosomes in particular may be responsible for their functions in skin regeneration and the immunomodulation field. The present review aims to gather the available information about the role of MSC-derived exosomes for both in vitro and in vivo models of different skin conditions and to highlight the need for further research in order to overcome any limitations for clinical translation.

Exosome-inflammasome crosstalk and their roles in inflammatory responses

Inflammasome is a complex of multiple proteins found in cytoplasm of the cells activated by infectious and/or non-infectious stimuli. This complex involves caspase-1 activation, leading to unconventional secretion of interleukin-1β (IL-1β) and IL-18 and inflammatory cascade. Exosome is the nanoscale membrane-bound extracellular vesicle that plays significant roles in intercellular communications by carrying bioactive molecules, e.g., proteins, RNAs, microRNAs (miRNAs), DNAs, from one cell to the others. In this review, we provide the update information on the crosstalk between exosome and inflammasome and their roles in inflammatory responses. The effects of inflammasome activation on exosomal secretion are summarized. On the other hand, the (dual) effects of exosomes on inhibiting and promoting inflammasome activation are discussed. Finally, perspectives on therapeutic roles of exosomes in human diseases and future direction of the research on exosome-inflammasome crosstalk are provided.

Skin Immunomodulation during Regeneration: Emerging New Targets

Adipose-Derived Stem Cells (ADSC) are present within the hypodermis and are also expected to play a pivotal role in wound healing, immunomodulation, and rejuvenation activities. They orchestrate, through their exosome, the mechanisms associated to cell differentiation, proliferation, and cell migration by upregulating genes implicated in different functions including skin barrier, immunomodulation, cell proliferation, and epidermal regeneration. ADSCs directly interact with their microenvironment and specifically the immune cells, including macrophages and T and B cells, resulting in differential inflammatory and anti-inflammatory mechanisms impacting, in return, ADSCs microenvironment and thus skin function. These useful features of ADSCs are involved in tissue repair, where the required cell proliferation, angiogenesis, and anti-inflammatory responses should occur rapidly in damaged sites. Different pathways involved have been reported such as Growth Differentiation Factor-11 (GDF11), Tumor Growth Factor (TGF)-β, Metalloproteinase (MMP), microRNA, and inflammatory cytokines that might serve as specific biomarkers of their immunomodulating capacity. In this review, we try to highlight ADSCs’ network and explore the potential indicators of their immunomodulatory effect in skin regeneration and aging. Assessment of these biomarkers might be useful and should be considered when designing new clinical therapies using ADSCs or their specific exosomes focusing on their immunomodulation activity.

Overview of current adipose-derived stem cell (ADSCs) processing involved in therapeutic advancements: flow chart and regulation updates before and after COVID-19

Adipose-derived stem cells (ADSCs) have raised big interest in therapeutic applications in regenerative medicine and appear to fulfill the criteria for a successful cell therapy. Their low immunogenicity and their ability to self-renew, to differentiate into different tissue-specific progenitors, to migrate into damaged sites, and to act through autocrine and paracrine pathways have been altogether testified as the main mechanisms whereby cell repair and regeneration occur. The absence of standardization protocols in cell management within laboratories or facilities added to the new technologies improved at patient's bedside and the discrepancies in cell outcomes and engraftment increase the limitations on their widespread use by balancing their real benefit versus the patient safety and security. Also, comparisons across pooled patients are particularly difficult in the fact that multiple medical devices are used and there is absence of harmonized assessment assays despite meeting regulations agencies and efficient GMP protocols. Moreover, the emergence of the COVID-19 breakdown added to the complexity of implementing standardization. Cell- and tissue-based therapies are completely dependent on the biological manifestations and parameters associated to and induced by this virus where the scope is still unknown. The initial flow chart identified for stem cell therapies should be reformulated and updated to overcome patient infection and avoid significant variability, thus enabling more patient safety and therapeutic efficiency. The aim of this work is to highlight the major guidelines and differences in ADSC processing meeting the current good manufacturing practices (cGMP) and the cellular therapy-related policies. Specific insights on standardization of ADSCs proceeding at different check points are also presented as a setup for the cord blood and bone marrow.

Exosomes: Their Role in Pathogenesis, Diagnosis and Treatment of Diseases

Simple Summary

The aim of this review is to provide an overview of the current scientific evidence concerning the role played by exosomes in the pathogenesis, diagnosis and treatment of diseases. The potential use of exosomes as delivery vectors for small-molecule therapeutic agents will be discussed. In addition, a special emphasis will be placed on the involvement of exosomes in oncological diseases, as well as to their potential therapeutic application as liquid biopsy tools mainly in cancer diagnosis. A better understanding of exosome biology could improve the results of clinical interventions using exosomes as therapeutic agents.

Abstract

Exosomes are lipid bilayer particles released from cells into their surrounding environment. These vesicles are mediators of near and long-distance intercellular communication and affect various aspects of cell biology. In addition to their biological function, they play an increasingly important role both in diagnosis and as therapeutic agents. In this paper, we review recent literature related to the molecular composition of exosomes, paying special attention to their role in pathogenesis, along with their application as biomarkers and as therapeutic tools. In this context, we analyze the potential use of exosomes in biomedicine, as well as the limitations that preclude their wider application.

Drug Delivery Systems of Natural Products in Oncology

In recent decades, increasing interest in the use of natural products in anticancer therapy field has been observed, mainly due to unsolved drug-resistance problems. The antitumoral effect of natural compounds involving different signaling pathways and cellular mechanisms has been largely demonstrated in in vitro and in vivo studies. The encapsulation of natural products into different delivery systems may lead to a significant enhancement of their anticancer efficacy by increasing in vivo stability and bioavailability, reducing side adverse effects and improving target-specific activity. This review will focus on research studies related to nanostructured systems containing natural compounds for new drug delivery tools in anticancer therapies.